The problems of policing or other radio-tracking of stolen or errant vehicles protected, as from theft, by the pre-installation in the vehicle by the owner of appropriate coded radio transponders triggerable by police-controlled command broadcast radio signals to transmit periodic reply signals that may be received by police tracking vehicles, has been admirably solved by systems of the type described, for example, in U.S. Pat. Nos. 4,818,998 and 5,917,423 and widely commercially operated as the LoJack® system, offered by the common assignee of the present application. When the tracking vehicle is homing in on the errant vehicle, the command broadcast signal, by police request, may be modified automatically to accelerate the periodicity of the transponder reply signals from the vehicle further to facilitate the tracking, as is also described in such patents.
Should the operator of the vehicle try to avoid being apprehended by the tracking vehicle and speed away, even after feigning stopping, the tracking process can readily be resumed by the police, and with safety, and may also involve notification to other police trackers of the code transmissions of the errant vehicle transponder.
When, however, an errant vehicle is not pre-equipped by the owner with such a stealth-protection transponder, both the safety of the police officer leaving the tracker vehicle and approaching a stopped vehicle on foot for inspection, as for remedial action for improper or dangerous operation of the vehicle, and the subsequent capability of re-catching a vehicle that has sped away, with the concomitant dangers of a high-speed and/or evasive chase, may be seriously jeopardized.
It is particularly to this kind of situation of police vehicle inspection of stopped vehicles in general that the present invention is primarily directed, being concerned with a novel technique that not only protects an officer approaching a stopped vehicle on foot, but provides for the external radio-transponder triggering of the vehicle for subsequent tracking, should the operator of the stopped vehicle decide to take off.